The applicant is a contractor involved in the erection of commercial buildings having unfinished walls made from prefabricated insulated panels. This type of prefabricated insulated panel is made by Insteel Corporation. Insulated walls may be substituted for concrete slab walls. These insulated walls are more inexpensively produced, transported, and erected than concrete slab walls. Not only is the material cost of a building having insulated walls substantially lower than that of the popular concrete slab building, but a finished building, having these insulated walls is generally preferred. The problem with these insulated building walls is not that the walls must be shot-created or sprayed with concrete. The problem is that the sprayed wall must be hand finished. Not only is hand finishing a time consuming and expensive process, but additionally, it is a difficult process that requires experience and skill to master. Many general contractors have regretted erecting prefabricated insulated walls after being unable to find a subcontractor who was able to satisfactorily hand finish a shot-creted surface to an acceptable flatness and finish.
In this application spray is defined to include any and all means of coating a wall with a slurry. And wall is defined to include any upright surface.